Carburetor of the pressure type



Jan. 2, 1962 H. w. MCCLAIN 3,015,548 CARBURETOR OF THE PRESSURE TYPE Filed July 28, 1958 N. l 5 E #Fis w United States Patent() 3,015,548 CARBURETOR F THE PRESSURE TYPE Harry W. McClain, 5460 El Parque, Long Beach 4, Calif. Filed July 28, 1958, Ser. No. 751,509 7 Claims. (Cl. 48-180) This invention relates to an improved carburetor of the pressure type, and particularly to one which feeds a gaseous fuel to an engine, this fuel being especially a hydrocarbon gaseous fuel such as propane or the like. This gaseous fuel is fed to the carburetor under pressures greater than atmospheric.

An object `of my invention is to provide a novel carburetor of the pressure type Where the incoming fuel passes through an intake tube and then past a needle valve, the needle valve being moved relative to a seat in the tube when the distributor disc moves under the impact of the incoming air and is pushed olf of its seat.

Another object of my invention is to provide a novel means of controlling the vacuum in the mixing chamber of the carburetor by the tension of a spring which presses the distributor disc against its seat.

Still another object is to provide a novel means of adjusting the needle valve relative to its seat in the intake tube; the adjustment of the needle valve being accomplished at the air intake side of the carburetor.

Still another object of my invention is to provide a novel carburetor of the pressure type in which the distributor disc has a single outlet which is always directed towards the fuel outlet port of the carburetor.

Still another object of my invention is to provide certain air bleeds around the fuel intake tube to prevent guniming up of the bearing surfaces on the intake tube due to accumulation of fuel on these surfaces.

Other objects, advantages and features of invention may appear from the accompanying drawings, the subjoined detailed description and the appended claims.

In the drawing:

FIGURE 1 is a longitudinal sectional view of my improved carburetor of the pressure type.

FIGURE 2 is a fragmentary transverse sectional view of the carburetor governor for use with variable speed engines.

FIGURE 3 is a fragmentary transverse sectional View of another type of governor for use in engines where rapid control is desirable.

Referring more particularly to the drawing, the numeral 1 indicates the entire carburetor housing which includes an air intake section 2 and arnixing section 3 which are substantially in axial alignment. The air sec- 'tion 2 includes an air intake port 4 and the mixing section 3 includes an outlet port 5 which extends into the intake manifold 6 of the engine, all of which is usual and well known. A transverse wall 6 separates the intake section 2 and the mixing section 3 and this wall is formed with the central opening and seat 7, the purpose of which will be further described. A distributor disc 8 is mounted for movement relative to the seat 7 in a manner `to be subsequently described, and this disc is provided with a single outlet duct 9 which extends towards the carburetor outlet at all times so that the incoming fuel passes directly towards the outlet of the carburetor and will not pass over any of the Working parts on the inside of the carburetor. Thus these Working parts are not coated or covered With the fuel or any of the additives thereto.

A fuel tube 10 is positioned within the air section 2 of the carburetor, and this tube extends through the wall of the carburetor so that a fuel pipe 11 may be attached thereto. Fuel under pressure passes through the pipe 11, thence into the tube 10 and then into the axially extending portion 12 of the tube 10; the tube 12 forming a 3,015,548 Patented Jan. 2, 1962 metering iet or intake of the carburetor. The coacting parts of this metering jet will be subsequently described. The tubes 10 and 12 may be integrally formed or cast with the body or housing of the carburetor, or these parts may be separately formed and then suitably mounted. The disc or valve 8 has a post 13 projecting from one side thereof and this post extends into a sleeve 14 which is iixedly mounted in the head 15 attached to one end of the housing 1 of the carburetor. A spring 16 within the sleeve 14 bears against the upper end of the post 13, and this spring also extends into a thimble 17 which screws into the outer end ofthe sleeve 14. By threading the thimbie 17 into or out `of the sleeve 14 the spring 16 can be tensioned properly to urge the post 13 and the disc 8 thereon onto the seat 7. The post 13 is counterbored ,las shown at 18 and slidably receives the shaft 19 on the lower end of which shaft the metering valve 20 is mounted. A. spring 21 within the bore 18 bears against the shaft 19 to press the metering jet 20 against a seat in the open end rof the tube 12.

To adjust the metering valve `20 relative to its seat in the .Itube 12, I provide a rod 22 which threads through the disc 8 and projects towards the air intake port 4 of the carburetor so that it can be reached from this air intake. The inner end of the rod 22 attaches to a pin 23 which projects from the shaft 19 and extends through a suitable slot in the post 13.

A tubular projection or sleeve 25 extends from the disc 8 in the opposite direction from the post 13, and this sleeve extends over the fuel intake tube 12 and slides on ythe outer surface of this tube so as to accurately guide the movement of the disc 8. To prevent fuel accumulation or other metallic substances on the outside of the :tube 12 a number of air ports 26 are provided in the sleeve 25, and these ports extend into the annular space 27 between the sleeve 25 and vthe outside of the tube 12. Thus air passing through the ports 26 and through the space 27 will sweep any fuel or fuel yadditives off of the bearing surface of the tube y12 and will cause the fuel and the like to pass out through the outlet duct 9, together with the incoming fuel.

An annular lip 2S on the face of the disc 8 opposite its seating face prevents turbulence below this lip, and enables the fuel to ilow more eifectively through the duct 9 and thence into the mixing chamber 3 of the carburetor.

A power assembly 39 includes a tube 31 which extends into the wall of the carburetor adjacent the fuel intake tube 10. A duct 32 extends from the tube 16 to the upper end of the power tube 31. A second duct 33 extends from the tube 31 through the wall of the housing and thence into the carburetor outlet port 5. A seat 34 in the upper end of the tube 31 is positioned between the ducts 32 and 33. A needle valve 35 projects from a exible diaphragm 36 at its one end. The other end of the valve extending to the seat 34 and cooperating therewith. A spring 37 in the thimble 38 bears against the diaphragm 36 or the end of the needle -35 to urge that needle olf of the seat 34 and thus open the duct 32 to the duct 33. A pipe 39 extends from a source of vacuum, such as the intake manifold of the engine, and thence to the lower side of the diaphragm 36. Thus the vacuum opposes the tension of the spring 37, tendingto urge the needle valve 35 onto its seat and closing the passage between the ducts 32-33. Under normal engine operation the vacuum in the pipe 39 will hold the valve 35 on its seat and thus close the passage between the ducts 32-33. If the throttle valve is opened wide the vacuum drops and the spring 37 will unseat the valve 35, thus permitting fuel to flow from duct 32 to 433 and thence into the carburetor outlet'S for additional power.

In FIG. 2 I have shown a modied type of governor for the carburetor which is substituted for the lsleeve 14, spring V16 and thimb'le 17, previously described. This governor consists of an inclosure 40 into one side of which the post \13 extends. A flexible diaphragm 41 extends transversely across the inclosure 40 and the diaphragm bears against the Yinner end of the post `13 as shown. A pipe 42 extends into the inclosure 40 on one side of the diaphragm 41 to admit fuel or air under pressure. A ball relief valve 43 is provided in the inclosure 40 on the same side that the fuel or air pressure is admitted, for the purpose of relieving excessive pressure within the inclosure. The other side of the diaphragm 41 from the pressure side is bled to the air through the port 44. This particular governor is advantageous for variable speed engines and the position of the disc 8 is thus controlled by fuel or air pressure which varies with the speed of the engine.

In FIG. 3 I have shown another form of governor for rapidly acting engines, or where it is desirable to adjust the carburetor parts to varying engine speeds. This governor consists of an inclosure 45 into which the post 13 extends as shown. A transversely extending flexible diaphragm 46 is mounted within the inclosure 45. This diaphragm is pressed against the post 13 to urge the disc 8 towards its Vseat by the pin 47 which, in turn, is actuated by the spring 48. A port 49 in the inclosure 4S admits pressure from the mixing chamber 3 of the carburetor to one side yof the diaphragm 46. A second duct 5t) also admits pressure from the mixing chamber 3 to the other side of the diaphragm 46. The ports 49* and 50 being small will not balance the diaphragm 46 and thus the spring 48 will react before the ports 49 and 50 can create a pressure balance in the inclosure 45, For engines which are changing their speeds rapidly this construction might be desirable.

In operation Fuel under pressure enters through the fuel pipe ,11 and thence through the tubes and 12 to unseat the metering valve and permit fuel to tlow through the single outlet port 9 of the disc S, and thence into the outlet 5 of the carburetor to the engine. When the engine starts the disc 8 is unseated and air flows from the air intake 4 and thence around the disc S, carrying with it the fuel from the port 9 and mixing the fuel and the air in the chamber 3. The mixed air and fuel then pass out through the outlet port 5. The movement of the disc 8 relative to the vseat 7 is controlled by the spring .i6 which tends to seat the disc 8. The metering valve 20 is adjusted relative to its seat by the rod 22 and the spring 21, acting against the post 19, will tend to press the metering valve 20 towards its seat subject, however, to the positioning of that valve on its seat by the adjusting rod 22. Movement of the disc 8 and its post 13 will also move the metering valve 20 relative to the tube 12 to vary the quantity of fuel admitted to the carburetor and determined by the amount of air coming into the carburetor past the disc 8, which air volume varies with Ythe speed of the engine. For sudden -fuel needs of the engine-particularly when the intake manifold pressure drops, the power assembly is activated in that the spring 37 unseats the needle valve permitting fuel to be injected directly through the ducts 32-33 and thence into the carburetor outlet 5.

Having described my invention, I claim:

1. A carburetor of the pressure type comprising a housing, said housing having a mixture outlet thereon `and a connection means to attach said mixture outlet to an intake manifold, said housing having an air intake therein spaced from said mixture outlet, a seat within said housing arranged between said mixture outlet and said air intake, a fuel intake tube positioned within said housing, a fuel pipe extending into one end of the tube, the other end of said tube being positioned adjacent said seat, a disc positioned within the housing and resting on the seat in one position of the disc to close the air passage between the air intakeand the mixture outlet, said disc having a single outlet Vduct therein, said duct extending towards said mixture outlet, a sleeve extending from one side of said disc and telescoping over one end of the fuel tube, said sleeve being spaced from the fuel tube throughout a part of the length of the tube to provide a chamber between the sleeve and the fuel tube, said sleeve having ports therethrough extending into said chamber to admit air into the chamber, a metering valve, means adjustably mounting the metering valve on said disc, said metering valve extending into one end of the fuel tube to meter the fuel issuing therefrom, and means on the housing engaging said disc and urging said disc against said seat.

2. A carburetor of the pressure type comprising a housing, said housing having a mixture outlet thereon and a connection means to attach said mixture outlet to an intake manifold, said housing having an air intake therein spaced from said mixture outlet, a seat within said housing arranged between said mixture outlet and said air intake, a fuel intake tube positioned within said housing, a fuel pipe extending into one end of the tube, the other end of said tube being positioned adjacent said seat, a disc positioned within the housing and resting on the seat in one position of the disc to close the air passage between the air intake and the mixture outlet, said disc having a single outlet duct therein, said duct extending towards said mixture outlet, a sleeve extending from one side of said disc and telescoping over one end of the fuel tube, said sleeve being spaced from the fuel tube throughout a part of the length of the tube to provide a chamber between the sleeve and the fuel tube, said sleeve having ports therethrough extending into said chamber to admit air into the chamber, a metering valve, means adjustably mounting the metering valve on said disc, said metering valve extending into one end of the fuel tube to meter the fuel issuing therefrom, and means on the housing engaging said disc land urging said disc against said seat, an adjusting rod threaded through the disc, a shaft slidably mounted in said disc, means attaching said shaft to the metering valve at one end of the shaft, and means coupling said shaft and said rod whereby rotation of said rod will adjust the shaft and the metering valve relative to said disc.

3. A carburetor of the pressure type comprising a housing, said housing having a mixture outlet thereon and a connection means to attach said mixture outlet to an intake manifold, said housing having an air intake therein spaced from said mixture outlet, a seat within said housing arranged between said mixture outlet and said air intake, a fuel intake tube positioned within said housing, a fuel pipev extending into one end of the tube, the other end of said tube being positioned adjacent said seat, a disc positioned within the housing and resting on the seat in one position of the disc to close the air passage between the air intake and the mixture outlet, said disc having a single outlet duct therein, said duct extending towards said mixture outlet, a sleeve extending from one side of said disc and telescoping over one end of the fuel tube, said sleeve being spaced from the fuel tube throughout a part of the length of the tube to provide a chamber between the sleeve and the fuel tube, said sleeve having ports therethrough extending into said chamber to admit air into the chamber, a metering valve, means adjustably mounting the metering valve on said disc, said metering valve extending into one end of the fuel tube to meter the fuel issuing therefrom, and means on Vthe housing engaging said disc and urging said disc engaging said shaft and pressing said shaft and metering valve into the fuel tube.

4. A carburetor of the pressure type comprising a housing, said housing having a mixture outlet thereon and a connection means to attach said mixture outlet to an intake manifold, said housing having an air intake therein spaced from said mixture outlet, a seat within said housing arranged between said mixture outlet and said air intake, a fuel intake tube positioned within said housing, a fuel pipe extending into one end of the tube, the other end of said tube being positioned adjacent said seat, a disc positioned within the housing and resting on the seat in one position of the disc to close the air passage between the air intake and the mixture outlet, said disc having a single outlet duct therein, said duct extending towards said mixture outlet, a sleeve extending from one side of said disc and telescoping over one end of the fuei tube, said sleeve being spaced from the fuel tube throughout a part of the length of the tube to provide a chamber between the sleeve and the fuel tube, said sleeve having ports therethrough extending into said chamber to admit air into the chamber, a metering valve, means adjustably mounting the metering valve on said disc, said metering valve extending into one end of the fuel tube to meter the fuel issuing therefrom, a sleeve mounted in said housing, a post projecting from the disc and extending into said last named sleeve, and spring means within the sleeve engaging the post to urge said disc against said seat.

5. A carburetor of the pressure type comprising a housing, said housing having a mixture outlet thereon and a connection means to attach said mixture outlet to an intake manifold, said housing having an air intake therein spaced from said mixture outlet, a seat within said housing arranged between said mixture outlet and said air intake, a fuel intake tube positioned within said housing, a fuel pipe extending into one end of the tube, the other end of said tube being positioned adjacent said seat, a disc positioned within the housing and resting on the seat in one position of the disc to close the air passage between the air intake and the mixture outlet, said dise having a single outlet duct therein, said duct extending towards said mixture outlet, a sleeve extending from one side of said disc and telescoping over one end of the fuel tube, said sleeve being spaced from the fuel tube throughout a part of the length of the tube to provide a chamber between the sleeve and the fuel tube, said sleeve having ports therethrough extending into said chamber to admit air into the chamber, a metering valve, means adjustably mounting the metering valve on said disc, said metering valve extending into one end of the fuel tube to meter the fuel issuing therefrom, a governor on said housing comprising an inclosure, a flexible diaphragm extending across said inclosure, a post extending from said disc and into the housing and bearing against the diaphragm, and pressure means in the inclosure and bearing against one side of the diaphragm to press said post and the disc thereon towards said seat.

6. A carburetor of the pressure type comprising a housing, Said housing having a mixture outlet thereon and a connection means to attach said mixture outlet to an intake manifold, said housing having an air intake therein spaced from said mixture outlet, a seat within said housing arranged between said mixture outlet and said air intake, a fuel intake tube positioned within said housing, a fuel pipe extending into one end of the tube, the other end of said tube being positioned adjacent said seat, a disc positioned Within the housing and resting on the seat in one position of the disc to close the air passage between the air intake and the mixture outlet, said disc having a single outlet duct therein, said duct extending towards said mixture outlet, a sleeve extending from one side of said disc and telescoping over one end of the fuel tube, said sleeve being spaced from the fuel tube throughout a part of the length of the tube to provide a chamber between the sleeve and the fuel tube, said sleeve having ports therethrough extending into said chamber to admit air into the chamber, a metering valve, means adjustably mounting the metering valve on said dise, said metering valve extending into one end of the fuel tube to meter the fuel issuing therefrom, and means on'the housing engaging said disc and urging said disc against said seat, a power assembly consisting of a tube mounted in said housing, a needle valve Within said tube, a seat in the tube, said needle valve extending to the seat and cooperating therewith, a vacuum pipe extending from said tube, means on said needlel valve adapted and arranged to be actuated by vacuum, a first duct extending from the fuel intake tube to one side of said last named seat, and a second duct extending from the other side of the last named seat to said mixture outlet.

7. A carburetor of the pressure type comprising a housing, said housing having a mixture outlet thereon and a connection means to attach said mixture outlet to an intake manifold, said housing having an air intake therein spaced from said mixture outlet, a seat within said housing arranged between said mixture outlet and said air intake, a fuel intake tube positioned within said housing, a fuel pipe extending into one end of the tube, the other end of said tube being positioned adjacent said seat, a disc positioned within the housing and resting on the seat in one position of the disc to close the air passage between the air intake and the mixture outlet, said disc having a single outlet duct therein, said duct extending towards said mixture outlet, a sleeve extending from one side of said disc and telescoping over one end of the fuel tube, said sleeve being spaced from the fuel tube throughout a part of the length of the tube to provide a chamber between the sleeve and the fuel tube, said sleeve having ports therethrough extending into said chamber to admit air into the charnber, a metering valve, means adjustably mounting the metering valve on said disc, said metering valve extending into one end of the fuel tube to meter the fuel issuing therefrom, and means on the housing engaging said disc and urging said disc against said seat, an adjusting rod threaded through the disc, a shaft slidably mounted in said disc, means attaching said shaft to the metering valve at one end of the shaft, and means coupling Said shaft and said rod whereby rotation of said rod will adjust the shaft and the metering valve relative to said disc, and spring means engaging said shaft and pressing said shaft and metering valve into the fuel tube, a power assembly consisting of a tube mounted in said housing, a needle valve within said tube, a seat in the tube, said needle valve extending to the seatand cooperating therewith, a vacuum pipe extending from said tube, means on said needle valve adapted and arranged to be actuated by vacuum, a first duct extending from the fuel intake tube to one side of said last named seat, and a second duct extendnig from the other side of the last named seat to said mixture outlet.

References Cited in the tile of this patent UNITED STATES PATENTS I1,361,529 Marr Dec. 7, 192() 1,376,343 Lamb Apr. 26, 1921 1,606,491 Abernathy et al. Nov. 9, 1926 1,813,206 Shipman July 7, 1931 2,587,165 Jones Feb. 26, 1952 

1. A CARBURETOR OF THE PRESSURE TYPE COMPRISING A HOUSING SAID HAVING A MIXTURE OUTLET THEREON AND A CONNECTION MEANS TO ATTACH SAID MIXTURE OUTLET TO AN INTAKE MAINFOLD SAID HOUSING HAVING AN AIR INTAKE THEREIN SPACED FROM SAID MIXTURE OUTLET, A SEAT WITHIN SAID HOUSING ARRANGED BETWEEN SAID MIXTURE OUTLET AND SAID AIR INTAKE A FUEL TUBE POSITIONED WITHIN SAID HOUSING A FUEL PIPE EXTENDING INTO ONE OF THE TUBE THE OTHER OF SAID TUBE BEING POSITIONED ADJACENT SAID SEAT, A DISC POSITIONED WITHIN THE HOUSING AND RESTING ON THE SEAT IN ONE POSITIONE OF THE DISC TO CLOSE THE AIR PASSAGE BETWEEN THE AIR INTAKE AND THE MIXTURE OUTLET SAID DISC HAVING A SINGLE OUTLET DUCT THEREIN SAID DUCT EXTENDING TOWARDS SAID MIXTURE OUTLET, A SLEEVE EXTENDING FROM ONE SIDE OF DISC AND TELESCOPING OVER ONE END OF THE FUEL TUBE, SAID SLEEVE BEING SPACED FROM THE FUEL 